1961 Austin A 105 Tires

The 1961 Austin A 105 uses two primary tire sizes: 640-15 in bias-ply construction and 185R15 in radial construction. Both sizes are built for 15-inch rims, so the choice is less about wheel diameter and more about whether the car is being kept in a traditional bias-ply configuration or fitted with a radial alternative.

That distinction matters because tire construction changes both appearance and setup requirements. A 640-15 keeps the vintage numeric sizing style, while 185R15 moves to a Euro-metric radial format. Before selecting either one, confirm the actual wheel width on the car and check for any past wheel, suspension, or stance changes that could affect compatibility.

The tire fitments used on the 1961 Austin A 105 are built around a 15-inch rim diameter. That applies to both the 640-15 bias-ply size and the 185R15 radial size, so wheel diameter remains consistent even though the tire constructions and sizing systems differ.

Rim diameter is only the first measurement to confirm. Wheel width also affects tire choice, especially when comparing bias-ply and radial options, because the available products do not all share the same width range. Measuring the wheel before ordering is a smart step on any collector car that may have replacement wheels or older restorations.

640-15 is a vintage numeric bias-ply tire size. The 640 portion refers to an approximate 6.40-inch nominal section width, and the 15 identifies the wheel diameter in inches. On the 1961 Austin A 105, this is the traditional bias-ply fitment and represents the older sizing system commonly seen on cars from this period.

Understanding that format helps when comparing it to 185R15, which is a radial size written in a different system. The two sizes are not simply different labels for the same tire, so selection should account for wheel width, intended appearance, and whether the goal is a period-style driving setup or a radial-based alternative for road use.

640-15 is a bias-ply tire size for the 1961 Austin A 105. It uses the older numeric sizing format and is offered in several bias-ply product lines, including blackwall, narrow whitewall, and wide whitewall versions that suit a traditional early 1960s appearance.

That makes 640-15 the size to consider when maintaining the car’s vintage tire presentation. It is different from the 185R15 radial option, even though both fit a 15-inch rim. Choosing between them should involve a look at the actual wheel width, the car’s restoration direction, and whether originality in appearance or radial-style road manners matters more.

Radial equivalents for 640-15 include 175R15 as an 80-series metric radial, P175/75R15 as a 75-series P-metric radial, and P185/70R15 as a 70-series P-metric radial. These are equivalent-size options for comparison when moving away from the original-style numeric bias-ply format.

Each option uses a different sizing convention and should be evaluated as an alternative rather than assumed to be interchangeable. A recommended rim-width range of 5 to 6 inches applies to these equivalents, and the final choice should also account for the car’s actual wheel dimensions, body clearance, and how closely the owner wants to retain a vintage visual profile.

Start by confirming the actual wheel size on the car, especially width as well as diameter. The 1961 Austin A 105 can use a radial fitment, but a conversion from 640-15 bias-ply to a radial equivalent or to 185R15 should begin with wheel compatibility, since radial tires often call for different width ranges than vintage bias-ply products.

Clearance is the next check. Steering lock, fender space, suspension condition, and ride height all deserve attention before changing construction. It also helps to decide whether the goal is a more traditional appearance or a radial-based road setup, because that choice will shape whether a Euro-metric radial or a P-metric equivalent makes the most sense.

The main considerations are sidewall style, brand, tire series, and wheel-width compatibility. In 640-15, the 1961 Austin A 105 has bias-ply choices from BFGoodrich, Firestone, Avon, and Excelsior, with blackwall, narrow whitewall, and wide whitewall options that can shift the car’s visual character quite a bit.

Selection should also reflect how the car will be used. A restoration-oriented Austin may call for a more traditional sidewall treatment, while a driver-focused car might put more emphasis on matching the tire to the wheel dimensions already on the vehicle. Reviewing the product’s rim-width range and load figure where stated helps narrow the field sensibly.

Sidewall choices for the 1961 Austin A 105 include blackwall, narrow whitewall, wide whitewall, and redline, depending on the tire size and series selected. The 640-15 bias-ply offerings carry the broadest whitewall variety, while 185R15 radial choices include blackwall, narrow whitewall, and redline versions.

That makes sidewall style one of the most noticeable appearance decisions on this car. A whitewall can push the Austin toward a more formal period presentation, while blackwall feels more restrained and redline adds a sportier vintage accent. The best choice depends on the car’s finish, restoration direction, and whether appearance or construction type is the first priority.

Tire choices for the 1961 Austin A 105 include Coker Classic, Michelin, Avon, Universal Vintage Tire, BFGoodrich, Firestone, and Excelsior. Those brands cover both 185R15 radial and 640-15 bias-ply fitments, giving owners several paths depending on whether the priority is construction type, tire series, or sidewall presentation.

Brand should be considered alongside the rest of the specification rather than by name alone. Some options differ in rim-width range, some in sidewall styling, and some in stated load figures or overall tire series character. Comparing those details within the correct size usually leads to a better decision than treating every tire in the size as the same.

For a period-style 1961 Austin A 105, the 640-15 bias-ply size is the natural starting point because it keeps the vintage numeric format and the traditional tire construction associated with cars of this era. It is also available in several appearance-focused versions, including blackwall, narrow whitewall, and wide whitewall styles.

The exact visual choice depends on the kind of restoration being pursued. Some owners want a simple blackwall look, while others prefer a more formal whitewall presentation. When exact originality matters, the best next step is to compare the tire choice against marque-club guidance, period photography, or vehicle-specific historical references rather than relying on size alone.

Tire construction changes the visual impression of a restored 1961 Austin A 105 as much as it changes the technical specification. A 640-15 bias-ply keeps the older sizing language and traditional profile associated with early 1960s fitment, while a 185R15 radial introduces a more modern-looking tire format on the same 15-inch wheel diameter.

That difference can be subtle from a distance and obvious up close, especially once sidewall style enters the picture. Whitewalls and redlines also influence how formal, sporting, or understated the car appears. Owners balancing show presentation with road use often weigh construction and sidewall treatment together rather than treating them as separate decisions.

Yes, modifications can affect tire fitment on a 1961 Austin A 105 even when the tire size itself is correct. Aftermarket wheels, changes in wheel width, suspension work, lowering, brake conversions, or body repairs can all alter the space available for a 640-15 or 185R15 tire.

That is why an older car should be measured as it sits today rather than assumed to match original dimensions. Checking wheel width, steering clearance, and fender room before choosing between bias-ply and radial tires helps avoid surprises. Any Austin carrying non-original wheels deserves that step before a final tire decision is made.

Before driving a 1961 Austin A 105 on new tires, inspect the wheels for correct diameter and width, verify that the tires are seated properly, and confirm there is no rubbing at full steering lock. It also makes sense to check inflation, valve condition, and overall clearance with the suspension loaded normally.

A collector car benefits from a wider pre-drive inspection as well. Look over steering and suspension components, watch for uneven ride height, and recheck fasteners if wheels have recently been installed. After a short initial drive, inspect the tires again for air loss, scuffing, or contact marks that could point to a fitment issue.

Collector-car tire care starts with regular pressure checks, visual inspections, and clean storage conditions. Whether the 1961 Austin A 105 runs 640-15 bias-ply tires or 185R15 radials, the tires should be inspected for cracking, bulges, cuts, uneven wear, and signs of slow air loss, especially if the car spends long periods parked.

Storage habits matter as much as mileage on a lightly used Austin. Keeping the car away from prolonged heat, direct sunlight, excess moisture, and ozone sources helps preserve the rubber over time. It also helps to inspect the tires before every longer drive, since age-related condition issues can appear even when tread depth still looks acceptable.